Foresight Update 11

page 2

Policy
Watch

by Stewart Cobb

As a result of the U.S. budget wrangling last fall, government
funding for research rose some twelve percent overall. Both
Congress and the President seem to believe, vaguely, that
research is good. Congress sees industrial technology as the key
to improving America's industrial competitiveness. It has boosted
funding for a wide range of "critical" or
"pre-competitive" technologies. Congress is also
contemplating a change to the research and experimentation tax
credit which could encourage more research by private companies.
Meanwhile, President Bush has concentrated his efforts on a few
specific initiatives, such as high-performance computing. [Nature,
348:97, 8Nov90; Science, p747,
9Nov90].

The bad news may be the way in which that money is being spent.
According to Nature [347:697,
25Oct90], NASA will receive some $13.9 billion this year, half
the Federal research budget. The National Science Foundation, by
contrast, will get only about $2.4 billion, roughly the cost of
NASA's newest Space Shuttle. Even ardent fans of manned
spaceflight may question these priorities, considering the
potential of new technologies for extending human capabilities in
space and elsewhere.

There's worse news in the method by which research money is now
being allocated: In the past, the science establishment worked
out a unified program each year and collectively lobbied Congress
for funding. Last year, however, a group of dissident biologists
split from the pack and hired their own lobbyist. [Nature348:270, 22Nov90] This is a dangerous precedent.
If other groups follow the biologists' lead, Congress may begin
distributing research funds on the basis of political pull,
rather than scientific merit (as perceived by the science
establishment). At best, this would mean worthy projects would
not be funded. At worst, scarce research money would be directed
to projects which could not possibly succeed.

The current budget contains at least one such project,
pork-barrelled by Senator Ted Stevens (R-Alaska). Senator Stevens
arranged a $34 million grant for the University of Alaska to
"harness the electrojet" as a source of electrical
power. The electrojet is an electric current high in the
ionosphere, related to the aurora borealis; tapping it for power
is about as practical as feeding lightning into the power grid.
The recipients of the grant, knowing it to be scientifically
unsound, managed to develop an elaborate rationalization which
allowed them to accept the money anyway [Nature, 348:101,
8Nov90]. Of course, $34 million would go a long way toward
developing nanotechnology.

The Commission of European Communities has decided to join
Japan's Human Frontier Science Program (HFSP). HFSP is the
Japanese government's leading international research program,
although international financial participation has been slow to
materialize. This new agreement means that smaller European
countries, outside the "G7" group of nations, will be
able to take part in the program. Several U.S. researchers have
received HFSP grants, but the U.S. government still views HFSP
with a certain amount of suspicion. Among other goals, HFSP is
investigating aspects of biochemistry and molecular assembly, a
possible path to molecular machinery. [Nature, 347:413,
4Oct90]

Two Englishmen have created a computer-based system for
extracting better decisions from a group of experts. The computer
asks the group a series of questions related to the decision, and
each individual enters his opinions on a numeric keypad. The
computer weights and tabulates the responses and displays the
combined result. So far, this is a standard technique from
decision analysis. But the computer also displays histograms of
the input data. This allows a moderator to isolate areas of
disagreement and investigate them further. One individual may
have an insight which others lack; the moderator can spot such
discrepancies on the histogram, and ask the stray to explain his
reasoning. From such debate can emerge a new consensus. In
theory, this happens at every committee meeting, but the new
software is much more effective in practice than the usual
meeting. The new system, called Teamworker, appears to be a
genuine advance in complex decision-making [Science,
250:367, 19Oct90].

Japan, meanwhile, is attempting to automate the ways in which
scientists exchange information. The new National Academic Center
for Science Information Systems (NACSIS) includes technical and
bibliographic databases and electronic mail services. The system
designers are paying particular attention to the users' needs for
communication. Some such tools are available in the U.S., but
only as a haphazard collection of parts designed for other uses [Nature,
347:561, 11Oct90].

The Japan Technology Transfer Association (JTTAS) is setting up a
research project into new computing technologies, including
neural and biological computing. This project, called the
International Institute of Novel Computing (IINC), is distinct
from the nascent "sixth-generation computer" project
proposed by Japan's well-known MITI (Ministry of International
Trade and Industry). JTTAS gets its funding largely from private
sources and says the two computer projects are complementary [Nature,
347:217, 20Sep90].

MITI recently announced that it would spend some $171 million
over the next ten years to study "microtechnology."
This term refers to miniature machines created by bulk
technology, not to molecular manufacturing, but in Japan these
techniques are seen as complementary. Germany is planning to
devote some $255 million over four years to similar research. The
National Science Foundation in the U.S. is supporting such
research at a level of $2 million a year. [Seattle Times,
7Sep90]

A recent paper by three Japanese researchers described a
reversible three-state photoelectrochemical reaction which might
be used to make extremely dense computer memories [Nature,
347:658, 18Oct90]. The researchers' affiliation
is intriguing: Department of Synthetic Chemistry, Faculty of
Engineering, University of Tokyo. In the U.S., synthetic chemists
insist on being described as pure scientists, despite their role
in designing and building molecular objects not found in nature.
Molecular engineering will progress faster when those who do it
feel as comfortable with the label "engineer" as do the
synthetic chemists at the University of Tokyo.

Stewart Cobb is an aerospace engineer and was an early member
of the MIT Nanotechnology Study Group.

Computational
Nanotechnology at PARC

Research in
nanotechnology continues to grow: the latest indicator is the
recent interest in computational nanotechnology here at the Xerox Palo Alto Research Center.
In December we bought a Silicon Graphics 4D/35 workstation (6
megaflops) and the Polygraf molecular modeling software from
BioDesign. This lets us model chemically stable structures with
as many as 20,000 atoms, including proposed bearings, mechanical
molecular logic elements, molecular structural elements, etc. In
the future we expect to get software that will model transition
states and reactive structures. Such quantum-mechanical
techniques are far more computationally intensive, restricting
analysis to ten or twenty atoms, but providing greater accuracy.

What does all this mean?

There is an accelerating trend towards modeling new designs
and new concepts on the computer before building them. GM has
found that "computational car crashes" on a CRAY are
cheaper, more flexible, and provide more information than real
car crashes. Pharmaceutical companies are investing heavily in
molecular modeling to investigate new drugs for similar reasons.
Xerox, at several different sites within the company and for
diverse reasons, is also pursuing this trend by modeling a range
of chemical systems.

Seen against this backdrop, work in computational
nanotechnology (at PARC or anywhere else) is simply a
continuation of the trend: before you build a car, a copier, or
an assembler, you should first model it on a computer. This lets
you review more designs more quickly and more cheaply before
actually building (expensive) physical systems; it reduces the
lag time from product conception to product delivery; and it
improves the quality of the final product.

While it's not entirely clear how long it will be until we
achieve a flexible molecular manufacturing capability, it *is*
clear that we will get there more quickly and with fewer false
starts if we model the components of such a system on a computer
before actually building them.

Computational Chemistry

Oversimplifying somewhat, there are two classes of molecular
modeling software: molecular mechanics systems and quantum
mechanical systems. Molecular mechanics usually treats the nuclei
of atoms as classical Newtonian point masses moving in a
potential energy function (or conservative force field) defined
by the electron cloud around them. There is no attempt to
determine where the electrons actually are, or even to worry
about the electrons at all. Rather, the positions of the nuclei
directly define the forces acting between them.

As an example, consider two hydrogen atoms bonded together to
form a molecule. As the nuclei move closer together, they repel
each other. As they move farther apart, they attract each other.
In equilibrium, the two nuclei will stay at a characteristic
distance. While this repulsion and attraction is actually the
result of a complex quantum mechanical interaction, it can be
summarized simply by noting the attractive or repulsive force
acting between the two hydrogen nuclei as a function of their
distance. A complex quantum mechanical interaction can be
accurately summarized by a simple graph. We don't know the actual
electron distribution that produced the forces acting on the two
nuclei, and we don't care.

This is known more formally as the Born-Oppenheimer
approximation: the nuclei swim in a sea of electrons, but if all
we are concerned about is the positions of the nuclei, then we
don't actually care where the electrons are: all we really care
about is the force field acting between the nuclei. The electrons
disappear from the computation and from our thinking, and are
replaced by the force field.

The Polygraf software from BioDesign uses the Born-Oppenheimer
approximation to greatly simplify the problem of modeling the
interactions between nuclei. By using structural data, heats of
formation, and vibrational frequencies determined experimentally
for many different compounds, it is possible to deduce a fairly
accurate representation of the force field that must be acting
between the nuclei. A carbon-carbon bond prefers to be a certain
length, while two hydrogens bonded to a single carbon have a
certain preferred angle between them. These and other similar
interactions form the building blocks of the force field. Once
this field is known, any structure can be modeled (with greater
or lesser accuracy), whether or not it was already known
experimentally.

Empirically derived force fields have been available for many
years. The better ones provide quite good results within the
broad range of compounds they were designed to handle. By using
this method, the geometry and interactions of chemically stable
structures (rods within a matrix, a molecular bearing on a
molecular shaft) can be modeled quite accurately.

This method has the great strength that a direct solution of
Schrödinger's wave equation is not required. The empirically
derived force field is used in its stead. It is this which allows
modeling of structures with tens of thousands of atoms and more.

Of course, because the force field is based on data derived from
chemically stable structures it does not provide information
about unstable structures or transition states. For this, it is
usual to compute an approximate solution to Schrödinger's
equation (including the electronic structure). This requires more
computational effort, but allows analysis of chemically unstable
species (e.g., free radicals) and transition states where bonds
are in the process of being made or broken.

Taken together, these two methods from computational chemistry
can model the mechanical interactions of large structures with
tens of thousands of atoms, and the chemical interactions of one
or two dozen atoms when bonds are being made and broken. These
are precisely the interactions that must be understood if we are
to build complex structures with atomic precision. As we apply
the methods of computational chemistry, a more detailed picture
of molecular manufacturing will emerge: a picture that will
shorten the path from today's limited abilities to the more
general abilities of the future.

Dr. Merkle's
interests range from neurophysiology to computer security; he is
a researcher at Xerox Palo Alto Research Center.

Position
Available: Research Associatein Molecular
Nanotechnology

A position will open in April 1991 for a Research Associate to
conduct theoretical research in molecular nanotechnology. This
position reports to K. Eric Drexler and is funded through a grant
from a newly-formed research institute in molecular engineering.

The Research Associate will:

co-author papers and articles on molecular devices,
molecular manufacturing, and their applications,

present these results at technical and other meetings.

Requirements

Candidates must have a good grounding in physics, some
substantial familiarity with chemistry, and an interest in
applying these to molecular engineering. Writing skills and
experience using computers are also required. Due to the
multidisciplinary nature of this work, an ability to learn
quickly through independent study is essential.

Desirable Characteristics

The successful candidate will have some characteristics in
common with those of the "ideal" candidate, as follows:

Has bachelor-degree--level (or better) knowledge of both
physics and chemistry, with a strong interest in
engineering.

Has published some research articles.

Reads extensively in the science and technology
literature.

Is enthusiastic about making a contribution to this
field.

For reasons of cultural compatibility, we prefer
candidates who routinely invest more than the traditional
forty hours/week in work and study. (Such a person
probably spends little or no time watching television.)

Rewards and Potential Career Path

The Research Associate position should be viewed as somewhat
similar to that of a graduate student; compensation comes in two
forms:

unique training in a newly emerging field, and

a living stipend (including any benefits) of slightly
over $20,000 per year.

We anticipate that someone who does well in this position will
eventually become an independent researcher, establishing his or
her own reputation as one of the first professionals to move into
this emerging field.

To apply

Interested applicants should forward one or more of the
following: resume, c.v., copies of published or unpublished
research work.

CPSR
Explores Nanotechnology

The Palo Alto chapter of the Computer Professionals for Social
Responsibility has recently formed a special interest group to
explore new technical developments, social consequences, and
potential benefits and dangers of nanotechnology. Founded by
Apple computer scientist Ted Kaehler, a
long-time participant in both CPSR and the Foresight Institute,
the group meets every two weeks to discuss all aspects of the
anticipated technology: implementation methods, applications, and
eventual effects on our lives. The group will soon visit a local
vendor of scanning tunneling and atomic force microscopes. For
more information contact Ted at 408-974-6241 or
kaehler2@applelink.apple.com. Meeting notices are sent to members
of the Palo Alto chapter of CPSR (you need not be a computer
professional to join), or can be obtained electronically from
Ted. CPSR can be reached at P.O. Box 717, Palo Alto, CA 94301.

Recent
Events

In February Eric Drexler
gave a plenary lecture on nanotechnology, titled "Toward 1015
MIPS" at the IEEE's Compcon computer conference held in San
Francisco, and later spoke on "Freedom of the Press for the
Press of the Future." A proceedings volume (including the
latter paper but not the plenary lecture) is available from IEEE
Computer Society Press, 10662 Los Vaqueros Circle, PO Box 3014,
Los Alamitos, CA 90720-1264; request order number 2134.

Earlier in February he presented the concept to the New Roles in
Society group at the American Association of Retired Persons,
which has stimulated an invitation to speak at an April meeting
of this group's steering committee. In January the MIT
Nanotechnology Study Group held an event at which a videotape on
nanotechnology was shown -- recorded at the Microelectronics and
Computer Technology Corporation (MCC) -- followed by a
telephone-linked question and discussion session.

In February, Ralph Merkle of
the Computational Nanotechnology Project at Xerox Palo Alto
Research Center spoke on nanotechnology at the Beckman Institute
at the California Institute of Technology, and at University of
Nevada at Las Vegas. The latter talk was sponsored by the
American Chemical Society chapter and the local office of the
Environmental Protection Agency.

Also in February, Dr. Merkle spoke on the same topic at the Xerox
Research Center of Canada. In earlier months, he gave a
well-received talk on silicon nanotechnology at the Frontiers of
Supercomputing II meeting at Los Alamos, followed by a special
evening session held on the topic.